SG6846ACSZ FAIRCHILD [Fairchild Semiconductor], SG6846ACSZ Datasheet - Page 2

• Manufacturer Part Number: SG6846ACSZ
• Description: Highly Integrated Green-Mode PWM Controller
• Manufacturer: FAIRCHILD [Fairchild Semiconductor]

Highly Integrated Green-Mode PWM Controller
MARKING DIAGRAMS
ORDERING INFORMATION
Part Number
PIN DESCRIPTIONS
© System General Corp.
Version 1.1.1 (IAO33.0059.B1)
SG6846ALSZ
SG6846ACSZ (Preliminary)
1
2
3
4
5
6
7
8
Pin No. Symbol
XXXXXXXXYWWV
SG6846AFTP
GND
FB
VIN
RI
RT
SENSE
VDD
GATE
Function
Detection
Setting
Detection
Ground
Feedback
Line-voltage
Reference
Temperature
Current Sense
Power Supply
Driver Output
OCP Latch
Yes
No
F:
T: S=SOP
P :
XXXXXXXX: Wafer Lot
Y: Year; WW: Week
V: Assembly Location
auto-recovery
L=OCP Latch, C=OCP
Null=regular package
Z=Lead Free
Description
determined in response to the signal from this pin and the current-sense signal from Pin 6.
hysteresis. Constant output power limit over a universal AC input range is also achieved using
this VIN pin. Consider adding a low-pass filter to filter out line ripple on the bulk capacitor.
switching frequency. Increasing the resistance reduces the switching frequency. Using a
26kΩ resistor results in a 65kHz switching frequency.
GND pin. The impedance of the NTC decreases at high temperatures. Once the voltage of the
RT pin drops below a threshold, PWM output is disabled.
current limiting. If the switching current is higher than two thirds of the peak-current threshold
for longer than 100ms and V
protection is activated. If an output short over-current also occurs and lasts for 100ms and
V
especially suitable for SMPS with surge current output. It also has built-in 5ms soft-start time
as switching frequency operates at 65KHz.
circuit disables PWM output as long as V
Ground.
The signal from the external compensation circuit is fed into this pin. The PWM duty cycle is
Line-voltage detection. The line-voltage detection is used for brownout protection with
A resistor from the RI pin to ground generates a reference current source that determines the
For over-temperature protection, an external NTC thermistor is connected from this pin to the
Current sense. The sensed voltage is used for peak-current-mode control and cycle-by-cycle
Power supply. If an open-circuit failure occurs in the feedback loop, the internal protection
The totem-pole output driver for the power MOSFET, internally clamped below 18V.
AUX
is lower than 12V, SG6846A turns off immediately. This two-level OCP feature is
Pb-Free
- 2 -
DD
is higher than 12V and lasts for 1700ms, over-current
Package
8-Pin SOP
8-Pin SOP
GND
FB
VIN
RI
DD
exceeds the threshold.
www.sg.com.tw • www.fairchildsemi.com
PIN CONFIGURATION
Product Specification
September 26, 2007
GATE
VDD
SENSE
RT
SG6846A